The present invention is directed to an air conditioning system such as a self contained unit ventilator or similar system having a blower or fan discharging air into a discharge duct. More particularly, the present invention is directed to the optimum scroll housing about the fan or blower and to the optimum discharge diffuser design. Alternatively, the invention is also applicable to terminal devices such as fan coil units.
A self contained unit ventilator is a typical packaged air conditioner in that it contains a complete air conditioning system including a serially linked indoor heat exchanger, compressor, outdoor heat exchanger, and an expansion device leading back to the indoor heat exchanger. The outdoor heat exchanger is in fluid communication with outdoor ambient air and, unless the unit ventilator is configured as a heat pump, acts as a condenser. The indoor heat exchanger is in fluid communication with the space to be conditioned and typically acts as an evaporator. The self contained unit ventilator is typically used in classroom or hotel applications and the incremental reduction of size of the unit ventilator provides significant competitive advantages.
Typically the indoor and outdoor sections are separated from each other by a physical barrier and each section includes a blower or fan moving air through the respective indoor or outdoor heat exchanger. For purposes of the present invention, the term blower and the term fan are used interchangeably and are intended to apply to all air moving devices. The blower or fan is often a cross flow tangential blower having a scroll housing about it where the fan's discharge leads into a discharge/diffuser duct. The scroll housing radially expands about the blower and guides the blower's discharge into the diffuser duct. A cutoff separates the blower input from the blower discharge.
It is desirable to minimize the fan's energy consumption while maximizing the diffusion of the fan's output. It is even more important to minimize the generation and radiation of acoustical sounds by the overall unit ventilator and particularly by the blower.